Di Simone Alessio
Department of Electrical Engineering and Information Technology, University of Naples Federico II, Naples 80125, Italy.
Sensors (Basel). 2016 Jun 25;16(7):971. doi: 10.3390/s16070971.
Synthetic Aperture Radar (SAR) imagery greatly suffers from multiplicative speckle noise, typical of coherent image acquisition sensors, such as SAR systems. Therefore, a proper and accurate despeckling preprocessing step is almost mandatory to aid the interpretation and processing of SAR data by human users and computer algorithms, respectively. Very recently, a scattering-oriented version of the popular SAR Block-Matching 3D (SARBM3D) despeckling filter, named Scattering-Based (SB)-SARBM3D, was proposed. The new filter is based on the a priori knowledge of the local topography of the scene. In this paper, an experimental sensitivity analysis of the above-mentioned despeckling algorithm is carried out, and the main results are shown and discussed. In particular, the role of both electromagnetic and geometrical parameters of the surface and the impact of its scattering behavior are investigated. Furthermore, a comprehensive sensitivity analysis of the SB-SARBM3D filter against the Digital Elevation Model (DEM) resolution and the SAR image-DEM coregistration step is also provided. The sensitivity analysis shows a significant robustness of the algorithm against most of the surface parameters, while the DEM resolution plays a key role in the despeckling process. Furthermore, the SB-SARBM3D algorithm outperforms the original SARBM3D in the presence of the most realistic scattering behaviors of the surface. An actual scenario is also presented to assess the DEM role in real-life conditions.
合成孔径雷达（SAR）图像深受乘性斑点噪声的影响，这是相干图像采集传感器（如SAR系统）所特有的。因此，一个适当且准确的去斑预处理步骤几乎是必不可少的，以便分别帮助人类用户和计算机算法对SAR数据进行解释和处理。最近，人们提出了一种面向散射的流行SAR块匹配三维（SARBM3D）去斑滤波器版本，称为基于散射（SB）的SARBM3D。新滤波器基于场景局部地形的先验知识。本文对上述去斑算法进行了实验敏感性分析，并展示和讨论了主要结果。具体而言，研究了表面的电磁和几何参数的作用及其散射行为的影响。此外，还提供了SB-SARBM3D滤波器对数字高程模型（DEM）分辨率和SAR图像-DEM配准步骤的全面敏感性分析。敏感性分析表明，该算法对大多数表面参数具有显著的鲁棒性，而DEM分辨率在去斑过程中起着关键作用。此外，在表面存在最现实的散射行为时，SB-SARBM3D算法优于原始的SARBM3D。还给出了一个实际场景，以评估DEM在实际条件下的作用。
